Tonight, the pomp and palaver of ITV's 50th birthday celebrations reaches its zenith with the launch of Ant & Dec's Gameshow Marathon, a clamorous wheeze that will see the guffawing Geordies recreate a selection of the station's most popular gameshows using the original sets, rules and super, smashing, great catchphrases. While an inevitable concession to "modern" (ie rubbish) telly values is inherent in its deployment of celebrity contestants, ITV is effusive in its assertion that the series will otherwise obey the "original aims" of each of the featured quizzes. Hence, the likes of The Price Is Right, Sale Of The Century, Play Your Cards Right and, tremendously, Bullseye will be removed from a box under ITV's spare bed and invited to once again flex their uniquely mad joints, unhampered by any interference other than the harmless mugging of a couple of northerners with large foreheads.

It would not be unrealistic to predict that Ant & Dec's Gameshow Marathon will be a walloping success. Indeed, give or take the odd burst of ill-judged "irony", it can't fail. Why? The gameshow is a vital part of our cultural furniture. It's as British as chops and as binding a social agent as soap operas and hating the monarchy. In the 50-plus years that it has been dazzling viewers with its rudimentary questions, shoddy household goods and unapologetically superficial supper-club patter, its patent blend of avarice and empathy is as irresistible as ever.

While the gameshow has been a TV staple since the 1950s (early successes include live cash bonanza The 64,000 Question, boffin-friendly general-knowledge quiz Double Your Money and proto-Mr & Mrs brain-squeezer Do You Trust Your Wife?) it wasn't until the 1970s that the genre hit its stride. As Britain wilted under the weight of social deprivation, the gameshow thrived, with audiences tuning in in their grey-faced droves to its seemingly effortless - though, in reality, carefully honed - mix of escapism ("exotic" prizes, glamorous ladies, deafening theme tunes) and accessibility (approachable hosts, almost affordable household goods, working-class contestants in Jacquard tank-tops, etc). Despite the myriad quirks and gimmicks boasted by each programme, the formula behind these primetime knees-ups was - and, indeed, is - essentially the same. That is: a ferociously self-assured male presenter encourages members of the public to win a selection of covetable prizes by answering spectacularly simple questions. The requisite sauce quota was provided by ungenerously attired young women whose presence (weakly justified by their prize-presenting "duties") discouraged dads from switching over to Juliet Bravo, while the thermostat - maintained by hysterical audiences and incessant, startling musical intrusions - was permanently set at "WHOOPEE". Within these simple brackets, the gameshow became a master of innovation.

The Price Is Right asked bilious housewives in bat-wing jumpers to guess the price of bags of millet and tins of ravioli. Bullseye found bloated labourers hurling darts at a board the size of Norwich. Sale Of The Century saw passive-aggressive toff Nicholas Parsons goad thunderous thickos into buying tartan electric blankets and beige Teasmades at knock-down prices. While the sets wobbled and the broiling studio lights twinkled invitingly, the mascots provided a memorable embodiment of each series' modus operandi. Thus, Bullseye's bluff working-man ethos was encapsulated in a bull in a short-sleeved shirt, Blankety Blank's brilliantly withering self-deprecation lived on in the Blankety Blank chequebook and pen (unusable, naturally) and 3-2-1's incomprehensible awfulness thrived in the form of Dusty Bin, a sinister remote-controlled simpleton whose mute mirth, huge hands and occasional, doom-laden appearances ("he" was, lest we forget, a booby prize) were uncomfortably reminiscent of David Warner's "hapless molester" character from Straw Dogs. In 1978, Dusty Bin's construction cost Yorkshire Television £10,500, which is approximately £974m in today's money and thus really not cricket at all, especially considering the same effect could've been achieved by glueing a photo of Dennis Nielsen to a mop on a rollerskate.

However, what really allowed audiences to separate the Blankety Blanks from the Lucky Ladders was the calibre of the host. While the BBC's quiz-fronting magi were generally benevolent authoritarians (Terry Wogan, Paul Daniels, the deceptively unassuming and yet sardonically magnificent Les Dawson), ITV's lot looked like they'd been chucked out of a working men's club for falling asleep in a urinal (Ted Rogers, Jim Bowen, Lennie Bennett). Still, even today, their names light up the showbiz firmament like a selection of Elizabeth Duke sovereign rings in an Argos display case. Crowther, Forsyth, Monkhouse (the tangerine titan of the quiz-bearing set), Barrymore, Grayson, Dennis: each a glowing beacon of vaudevillian zest and living, giggling proof that there is nothing Britain likes more than the warm embrace of a tanned man in a Burton suit.

Sadly - if unsurprisingly - the gameshow's supremacy couldn't last. The early 1990s saw a hot gust of change. Postmodernism sniggered at its hammy trappings and increasingly enlightened viewers eschewed its innocent simplicity in favour of programmes that offered irony, boffing and blood. Though The Generation Game continued to garner huge audiences (due, at least in part, to the genuinely masterful presence of the once-loathsome Jim Davidson), elsewhere, ratings slumped like a depressed tramp in a doorway.

The arrival, in 1998, of Who Wants To Be A Millionaire saw the primetime quiz show enter a new, tertiary phase. With a set daubed in shades of black, a theme tune that sounds like it's heralding the death of an eastern European warlord, a brooding reputation (courtesy of "Coughing Major" Charles Ingram, the lantern-jawed lozenge at the spluttering centre of Strepsilgate) and the presence of Chris Tarrant - a gurgling satsuma in a polyester polo-neck - it's been responsible for a flurry of imitators, of which The Weakest Link is easily the least crap.

Ultimately, the gameshow never went away. It may exist in a reduced, glummer capacity but its offspring pepper today's schedules like buckshot. The latest is ITV's Cash Cab, in which a taxi serves as a portable quiz emporium. With its uneasy contestants, chirpy cockney host and no-frills cash prizes, it embodies the caveat upon which the gameshow built its empire: greed is good, but winning a Teasmade off a nice man on the telly is better. It would not be unreasonable to suggest that the gameshow has not merely come full circle, but is using the golden loop as a crown. Here's to another 50 years of glorious stupidity.

Britain's strangest quiz shows

Under Manning (ITV, 1981) Short-lived quiz created solely to allow Bernard Manning to award a prize (the "Bernard Under Manning") that could be reduced to the acroynm "BUM".

Cannon and Ball's Casino (ITV, 1990) Ageing comedians place their chips on this concept reviving their careers. The wheel span. And then fell off the table.

Why Did The Chicken? (BBC1, 1994) Child contestants collected eggs in this barnyard-based misfire. The timer was a giant descending hen. Obviously.

Win Beadle's Money (Five, 1999) Contestants went face to beard with beleaguered prankster Jeremy Beadle in an effort to win up to £1,000 of his personal fortune. Depressing.

The Answer Lies In The Soil (ITV, 1999) Baffling agrarian panel show in which nervous pensioners competed in such rounds as "Name That Seed" and "Crack That Nut".

Naked Jungle (Five, 2000) Few sounds are likely to repel viewers more than the damp thud of scrotum against bark